The purpose of this study was to determine if oral creatine (CR) ingestion, compared to a placebo (PL), would enable swimmers to maintain a higher swimming velocity across repeated interval sets over 2 weeks of supplementation. Fourteen female and 18 male university swimmers consumed a PL during a 2-week baseline period. Using a randomized, double-blind design, during the next 2 weeks subjects consumed either CR or PL. Swimming velocity was assessed twice weekly during 6 × 50-m swims and once weekly during 10 × 25-yd swims. There was no effect ofCR on the 10 × 25-yd interval sets for men and women and no effect on the 6 × 50-m interval sets for women. In contrast, for men, CR significantly improved mean overall swimming velocity in the 6 × 50-m interval after 2 weeks of supplementation, whereas PL had no effect. Although ineffective in women, CR supplementation apparently enables men to maintain a faster mean overall swimming velocity during repeated swims each lasting about 30 s; however, CR was not effective for men in repeated swims each lasting about 10-15 s.
The authors are with the Sport and Exercise Sciences Section, School of Physical Activity and Educational Services, The Ohio State University. Direct correspondence to Nicole Leenders, The Ohio State University, School of Physical Activity and Educational Services, 309E Pomerene Hall, 1760 Neil Ave., Columbus, OH 43210.